Lubricant using vegetable oil and having a self-generating friction film

ABSTRACT

A lubricant made from vegetable oil that can form a friction film when used. The lubricant has 86-99 wt % of vegetable oil that contains double bonds and bis-allylic protons, 10-0.5 wt % trans FAT, 3.6-0.3 wt % surfactant, and 0.4-0.2 wt % antioxidant. Additionally, the weight percentages of surfactant are 3.6˜0.3 wt %, and the weight percentages of antioxidant are 0.4˜0.2 wt %.

FIELD OF THE DISCLOSURE

The present disclosure relates in general to a lubricant, and moreparticularly, to the lubricant made from vegetable oil that canself-generate a friction film during usage.

BACKGROUND OF THE DISCLOSURE

Lubricants are very important substances because they can reduce energycosts and energy consumption, as well as prevent wear or damage toparts, thus prolonging the service life of mechanical parts.

The lubricants commonly used in the industry are usually made of eithermineral oil or synthetic oil, which is derived from petroleumderivatives and can be harmful to the environment when they arediscarded after each use. Therefore, mineral or synthetic oil-basedlubricants are considered as having environmentally unfriendlysubstances.

Currently known types of vegetable oil, such as palm oil as derived fromplants, is a triglyceride (TAG) that has a polar head group (polar headgroup) that is not present in mineral oil, and therefore allowingvegetable oil to better interact with metal surfaces. However, becauseof the high molecular weight and low volatility and high flash point,vegetable oil is chemically unstable. In addition, vegetable oilcontains double bonds and bis-allylic protons, which are easily attackedby free radicals, resulting in undesirable side effects. Therefore,vegetable oil alone is not an ideal lubricant.

Recently, there has been an increasing interest in self-generatedtribofilms, especially amorphous carbon (a-C) friction films, which canbe formed from friction of contact interfaces during, e.g., slidingtherebetween.

As such, it would be desirable for the vegetable oil to be added withadditives to yield a complex vegetable oil and formulate a novellubricant that can produce an amorphous carbon friction film during use.Such novel lubricant will not only make the lubrication effect betterand reduce wear, but will also be friendlier to the environment, andtherefore significantly change the market ecology of the conventionalmineral oil-based lubricant.

SUMMARY OF THE DISCLOSURE

It is therefore an object of the present disclosure to construct anoil-based lubricant using vegetable oil as the base.

A further object of the present disclosure is to have the vegetable oilbased lubricant self-generate a friction film during usage.

In order to achieve the above-mentioned objects, the present disclosureuses the vegetable oil as the base for the lubricant that can form afriction film when used. Specifically, the lubricant includes 86˜99 wt %vegetable oil containing double bonds and bis-allylic protons, 10˜0.5 wt% synthetic fat, 3.6˜0.3 wt % surface active agent, and 0.4˜0.2 wt %antioxidant. Synthetic FAT, 3.6˜0.3 wt % surface active agent, and0.4˜0.2 wt % antioxidant.

With the above-mentioned features, the present disclosure is friendlierto the environment when it is disposed of after use. In addition, thelubricating oil of the present disclosure can form an amorphous carbonfriction film during the process of use under pressure, which cangreatly improve the lubricating effect and further reduce the wear andtear.

BRIEF DESCRIPTION OF THE DRAWINGS

In order to illustrate the technical features of the present disclosurein detail, an exemplary embodiment is illustrated with drawings,wherein:

FIG. 1 is a schematic diagram showing test results of a first lubricanthaving palm oil as the type of vegetable oil according to a firstexemplary embodiment of the present disclosure;

FIG. 2 is a schematic diagram showing test results of a second lubricanthaving mineral oil instead of vegetable oil according to the firstexemplary embodiment of the present disclosure;

FIG. 3 is a comparative schematic diagram comparing the test results ofthe vegetable (palm) oil-based first lubricant and mineral oil-basedsecond lubricant of the first exemplary embodiment of the presentdisclosure;

FIG. 4 is a Raman shift diagram of the first exemplary embodiment of thepresent disclosure;

FIG. 5 is a schematic diagram showing test results of a third lubricanthaving palm oil as the type of vegetable oil according to a secondexemplary embodiment of the present disclosure;

FIG. 6 is a schematic diagram showing test results of a fourth lubricanthaving mineral oil instead of vegetable oil according to the secondpreferred embodiment of the present disclosure; and

FIG. 7 is a comparative schematic diagram comparing the test results ofthe vegetable (palm) oil-based third lubricant and mineral oil-basedfourth lubricant of the second exemplary embodiment of the presentdisclosure.

DETAILED DESCRIPTION OF THE EXEMPLARY EMBODIMENTS

In order to illustrate the technical features of the present disclosurein detail, the following exemplary embodiments are cited and illustratedwith accompanying drawings, among others.

As shown in FIGS. 1 to 4 , a first exemplary embodiment of the presentdisclosure is a first lubricant which uses vegetable oil as the base,and particularly palm oil as the type of vegetable oil (“first palmoil-based lubricant PF”) that can self-form a friction film when in use.The first palm oil-based lubricant PF is composed of 86 wt % vegetableoil with double bonds and bis-allylic protons, 10 wt % synthetic FAT,3.6 wt % surfactant, and 0.4 wt % antioxidant.

The aforementioned surface active agent has Fatty Alcohol Epoxide Groupwith 1.5 wt %, Polyethylene Glycol Oleate with 1.1 wt %, PolyethyleneGlycol Cetyl/Oleyl Ether with 0.3 wt %, and Sodium Stearate with 0.7 wt%. Polyethylene Glycol Cetyl/Oleyl Ether at 0.3 wt % and SodiumGualenate at 0.7 wt %. The four surface-active agents listed here areexamples, and in practice, one or more of the four surface-active agentscan be used in a mixture.

The aforementioned antioxidant in this embodiment is OctylatedDiphenylamine. In order to adjust the viscosity, the percentage of theantioxidant can be reduced to 0.2% by weight and a 0.2% viscositymodifier, such as polybutylene, can be added.

A four-ball lubrication tester (under the code of ASTM 2783) (not shownin the figure) is used to test the first palm oil-based lubricant PF.The ball tester is a standard test device for evaluating the performanceof oil-based products. The test results of the first palm oil-basedlubricant PF are shown in FIG. 1 . The part below point C as shown inFIG. 2 indicates good lubrication effect; between point C and point D isthe transition area before the load constitutes a scratch; between pointD and point E, the scratch size increases steadily with the increase ofthe load; and after point E, the failure of the lubricating oil PF makesthe scratch size increase significantly, which causes the fusion betweenthe upper ball and the lower ball. As such, point E in FIG. 1 is theeffective limit of the first palm oil-based lubricant PF.

In FIG. 2 , the result of the test conducted by the four-balllubrication test machine after replacing the aforementioned 86 wt % palmoil with 86 wt % mineral oil to become a mineral oil-based lubricatingoil (“mineral oil-based lubricant MF”). FIG. 3 shows the combinedresults of the ones as shown in FIGS. 1 and 2 . As illustrated in FIG. 3, the first palm oil-based lubricant PF has a higher load bearingcapacity than the mineral oil-based lubricant MF.

If a Raman spectra test is performed on the aforementioned lower ball,the dark material in the scratch on the surface of the aforementionedlower ball will show its test results. However, before the actual test,the first palm oil-based lubricant PF can be added with TricresylPhosphate (TCP) in order to generate more spectra during the Ramanspectroscopy test. However, since TCP is toxic to the environment, it isadded only for the convenience of performing the Raman spectroscopy. Inother words, it is not necessary to add TCP to the first palm oil-basedlubricant PF when not performing the Raman spectra test. The content ofthe Raman spectroscopy is shown in FIG. 4 , which has a dark material inthe scratch with a distinct G-band and D-band, indicating the presenceof hydrogenated amorphous carbon, especially a graphite peak at 1580cm-1 at 63 kg load and at 2900 cm-1. The testing process reveals thatthe first palm oil-based lubricant PF of the present disclosure can forman amorphous carbon friction film.

This first embodiment illustrates that the first palm oil-basedlubricant PF of the present disclosure is friendlier to the environment,and, in the process of use and when subjected to pressure (i.e., whensubjected to the pressure of objects rubbing against each other), it canform an amorphous carbon friction film, which greatly improves thelubrication effect and further reduces the wear of objects.

In addition, although palm oil is used in the first exemplary embodimentas the source of the vegetable oil, other types of vegetable oil can beused, particularly the ones containing double bonds and bis-allylicprotons, which can replace palm oil and have similar effects as thefirst palm oil-based lubricant PF.

As shown in FIGS. 5 to 7 , a second lubricant which uses vegetable oilas the base, and particularly palm oil as the type of vegetable oil(“second palm oil-based lubricant PF′”) that can self-form a frictionfilm when in use is disclosed as a second preferred embodiment of thepresent disclosure. The second palm oil-based lubricant PF′ is composedof 99 wt % vegetable oil containing double bonds and bis-allylicprotons, 0.5 wt % synthetic FAT, 0.4 wt % surface active agent, and 0.1wt % antioxidant. wt % of antioxidant.

The aforementioned surface active agent comprises Fatty Alcohol EpoxideGroup with 0.1 wt %, Polyethylene Glycol Oleate with 0.1 wt %,Polyethylene Glycol Cetyl/Oleyl Ether with 0.1 wt %, and Sodium Stearatewith 0.1 wt %. Polyethylene Glycol Cetyl/Oleyl Ether) at 0.1 wt % andSodium Gualenate at 0.1 wt %.

A four-ball lubrication tester (not shown in the figure) is used to testthe second palm oil-based lubricant PF′, and the test results are shownin FIG. 5 . FIG. 7 is a schematic diagram showing the combined resultsof the ones as shown in FIGS. 5 and 6 . As shown in FIG. 7 , the secondpalm oil-based lubricant PF′ in the second embodiment has a slightlyhigher point D than the mineral oil M′, and a slightly left point E thanthe mineral oil M′. In other words, the lubrication limit load isslightly worse than the mineral oil M′ and the size of the scratchproduced is larger; the lubrication limit load is slightly worse thanthat of mineral oil M′; and the size of the scratches produced islarger. Nonetheless, one or more needs of a user can be met when theuser does not have a high demand for lubrication, and the formation ofan amorphous carbon friction film can still be accomplished.

Even when the weight percentage of palm oil in the second embodiment isincreased to 99 wt %, a certain degree of lubricating effect is stillpresent while being more friendly to the environment, and theself-generation of the amorphous carbon friction film can still beachieved during usage.

The present disclosure has been described with reference to theexemplary embodiments, and such description is not meant to be construedin a limiting sense. It should be understood that the scope of thepresent disclosure is not limited to the above-mentioned embodiment, butis limited by the accompanying claims. It is, therefore, contemplatedthat the appended claims will cover all modifications that fall withinthe true scope of the present disclosure. Without departing from theobject and spirit of the present disclosure, various modifications tothe embodiments are possible, but they remain within the scope of thepresent disclosure, will be apparent to persons skilled in the art.

What is claimed is:
 1. A lubricant with vegetable oil as a base togenerate a friction film during usage, comprising: 99 wt % by weight ofvegetable oil containing double bonds and bis-allylic protons, 0.5 wt %by weight of trans FAT, 0.4 wt % by weight of surfactant, and 0.1 wt %by weight of antioxidant.
 2. (canceled)
 3. (canceled)
 4. The lubricantaccording to claim 1, wherein the surfactant is at least one of FattyAlcohol Epoxide Group, Polyethylene Glycol Oleate, Polyethylene GlycolCetyl/Oleyl Ether, and Sodium Gualenate.
 5. (canceled)
 6. The lubricantaccording to claim 1, wherein the antioxidant contains OctylatedDiphenylamine.
 7. The lubricant according to claim 1, wherein palm oilis the type vegetable oil used.